Indigo dyeing process and apparatus and indigo dyed yarns and fabrics made thereby
AssigneeIndigo Mill Designs, Inc.
InventorsHoward Malpass, Ralph Tharpe, M. Dean Ethridge
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Abstract
Processes and apparatus are disclosed which substantially eliminate the formation of oxidized indigo dye before and during dye application onto a natural fiber yarn or fabric while allowing the leuco-indigo dye molecule to diffuse fully into the natural fibers of the yarn where it can fix to the fibers prior to oxidation (i.e., exposure of the leuco-dyed yarns to oxygen). Indigo dyed textile products (e.g., dyed cotton yarns that may be twill woven to form a denim fabric) exhibit exceptionally high colorfastness as determined by the AATCC Crock Test.
Claims22
A continuous process for indigo dyeing of textile products comprising the steps of:
- (a) introducing an undyed textile product into an oxygen purge chamber having an inert atmosphere, the purge chamber comprising a purification system in fluid communication with the inert atmosphere therein;
- (b) transferring the undyed textile product from the purge chamber to a dye application chamber having an anaerobic atmosphere;
- (c) applying a leuco-indigo dye solution onto the undyed textile product within the anaerobic dye application chamber to form a leuco-indigo dyed textile product;
- (d) transitioning the leuco-indigo dyed textile product from the dye application chamber into an anaerobic dwell chamber to complete diffusion of the leuco-indigo dye within fibers of the textile product;
- and
- (e) discharging the leuco-indigo dyed textile product into an oxygen-containing atmosphere to oxidize the leuco-indigo dye applied to the textile product and thereby form an indigo-dyed textile product.
Dependencies are inferred from the claim text.